<!DOCTYPE html>
<html>
    <head lang="en">
        <meta charset="UTF-8">
    </head>
    <body maginheight="opx" maginwidth="0px">
        <table width="100%" height="950px" style="background-color:aquamarine">
             <tr>
                <td colspan="3" width="100%"  height="10%" style="background-color:blue">
头部
                </td>
             </tr>
             <tr>
                    <td width="20%" height="80%" style="background-color:blueviolet">
                        <ul>
                            <li>iso</li>
                            <li>html</li>
                            <li>sdfs</li>
                        </ul>  
                    </td>
                    <td width="60%" height="80%" style="background-color:red"> </td>
                    <td width="20%" height="80%" style="background-color:rgb(43, 174, 226)"></td>
            
                   
             </tr>
             <tr>
                 <td colspan="3" width="100%" height="10%" style="background-color:rgb(226, 131, 43)">
底部
                 </td>
             </tr>

        </table>
        
    </body>
</html>